You are correct Paul...I forgot about the "d16" diode already connected to the
"TX EN" jack ...only requiring one diode in the 87A relay line.
I will make up a cable and try this and report back.
Terry - W6RU
Paul Christensen wrote:
> A valid point Terry, although isolation may not be as good as the
> transistor, but then again, it may not need to be. In my case, I need the
> added isolation, because I create an open-collector amp key line for my
> choice of three amps and four rigs! In essence, I have a high isolation
> keyed buss line.
>
> Taking your suggestion, it appears that only one external diode is required.
> D16 performs the necessary isolation after summing on the TX EN line.
>
> It would be interesting to see if this works in conjunction with an RCA "Y"
> adapter, running two ends between TX OUT and TX EN, then running the third
> wire on out to the external diode and then the amp.
>
> In any event, let us know how this works using the external steering diode.
>
> 73,
>
> -Paul, W9AC
>
> -----Original Message-----
> From: w6ru <w6ru@lightspeed.net>
> To: Paul Christensen <paulc@mediaone.net>; tentec@contesting.com
> <tentec@contesting.com>
To: <tentec@contesting.com>
> Date: Sunday, September 20, 1998 8:47 PM
> Subject: Re: [TenTec] Omni QSK with Alpha's 87A QSK
>
> >Paul,
> >Your modification requires a person to go inside the radio and make a
> change to
> >a SMC circuit board in regards to Q16.
> >Q11's collector is already present at the "TX OUT" jack. This is what I am
> >suggesting Jim and others who do not want to get inside their radios, use
> to key
> >BOTH the "TX EN" jack and the "RELAY" jack on the 87A...through steering
> diodes
> >external to the radio. Take the keying line from the "TX EN" jack through a
> >diode...take the 87A "relay" jack line through a diode...sum them together
> into
> >the "TX OUT" jack.
> >
> >Terry - W6RU
> >
> >Paul Christensen wrote:
> >
> >> Terry:
> >>
> >> The steering diodes are not necessary. All the parts needed are already
> >> there. The input to R29 is bridged across the TX OUT line. Then, the
> >> collector of Q16 is sent directly to the RELAY RCA jack.
> >>
> >> End of Modification.
> >>
> >> -Paul, W9AC
> >>
> >> -----Original Message-----
> >> From: w6ru <w6ru@lightspeed.net>
> >> To: Jim Reid <jreid@aloha.net>; tentec@contesting.com
> >> <tentec@contesting.com>
To: <tentec@contesting.com>
> >> Date: Sunday, September 20, 1998 8:34 PM
> >> Subject: Re: [TenTec] Omni QSK with Alpha's 87A QSK
> >>
> >> >
> >> >My error !
> >> >This time I see the keying of this circuit...not sure why it didn't show
> >> the
> >> >first time.
> >> >THIS MAKES IT SIMPLE...
> >> >Just let that "TX OUT" jack key BOTH the "TX EN" jack on the Omni 6 AND
> key
> >> the
> >> >"RELAY" jack on the 87A. I would use two steering diodes, one in each
> >> circuit
> >> >to isolate the circuits from each other in the receive mode.
> >> >Hope this helps.
> >> >Terry - W6RU
> >> >
> >> >
> >> >--
> >> >FAQ on WWW: http://www.contesting.com/tentecfaq.htm
> >> >Submissions: tentec@contesting.com
> >> >Administrative requests: tentec-REQUEST@contesting.com
> >> >Problems: owner-tentec@contesting.com
> >> >Search: http://www.contesting.com/km9p/search.htm
> >> >
> >> >
> >>
> >
> >
>
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